I just hit 1K miles on my '09 AWD CTS 3.6 Di and decided it was time to change the Oil & Filter as this car will have to last me for a while. The previous post(s) were of some help as far as removing the upper engine shroud but the AWD has a different lower panel under the engine and the drain plug is not in the same location. So the proceedure starts similary when taking the upper engine shroud off you simply take out the oil filler cap and lift up on the left side of the shroud to overcome the pin/grommet attachment and then slide forward to remove. The lower engine cover has four 10mm bolts and two integral split plugs that snap into a receptacle. I used two small screw drivers to push on either side but I think the other side came right out on it's own once the weight of the cover was on it. Unfortunately I took the car off of the lift before I realized I hadn't taken a picture of the lower shroud on the car but the attached pictures should give anyone the general idea. The oil plug location was a little perplexing as at first one could conclude that it is the internal hex plug that is the Getrag transfer case drain. After checking on the forum to see if anything pointed to where the plug was, I decided it had to be the bolt with an integral washer, which it was. Unfortunately I didn't have a new flat washer gasket but it appeared OK and it didn't leak after I started the engine. I'll have to change that seal the next time around. All in all not too bad of a job especially with a lift but one I'm glad I did at 1k miles as the oil was darker than I expected. I used a Napa Gold filter P/N 7090. Normally I fill the filter with oil but I simply snapped the filter into the cover housing and tightened it up before I thought about the possibilty of pushing the filter down into the housing first and filling the housing with oil prior to putting the cover on. I'll try that next time but there was no audible top end noise on start-up and the oil pressure came up quick. It took 6 quarts of Mobil 1 5W-30 and it still could use another 1/2 quart to get it full. So for what it is worth that was my experience with an AWD 3.6L '09 CTS.

Nice job & good information! Thanks!
But changing oil at 1000 miles is a complete waste of time and money.
There have been reams of information debunking the 'oil change myths' and below is a pretty good synopsis:

Oil Change Intervals

Few subjects generate as much debate on Usenet as the proper oil change interval. Since few people bother with oil analysis the debate centers on time and mileage.

Follow the Money
Unfortunately, there are market forces that have a vested interest in convincing vehicle owners to change their oil more often than necessary. The legal prey of these market forces have become convinced that they are purchasing "cheap insurance" or "peace of mind" by changing their oil more often than necessary. Complicating things is the fact that doing oil changes is one of the few do-it-yourself maintenance tasks that is still within the ability of the backyard mechanic to perform.

Recreational Oil Changing
The term "recreational oil changer" was coined to define people that change their oil far more than necessary because they actually enjoy doing it. It's easy to understand the psychology behind the recreational oil changing. It's the visceral feel of the tools, the victory when that old oil filter breaks free, the hot dirty oil pouring out, the joy of oiling of the gasket on the new filter, that new copper or fiber gasket on the drain plug, the clean clear oil going in, and the sense of accomplishment when you start the car, the oil light comes on for a moment, then goes out. For $8-10 in oil and parts, it's pretty cheap entertainment, but if people would be content to do it only when it provides some benefit to the vehicle it would be better.

The 3000 Mile Myth
The 3000 mile oil change interval has been pounded into people's heads for decades. It had a scientific basis when engines used non-multi-weight, non-detergent oil. It no longer has any scientific basis, but it is still being promoted by certain entities, most notably the oil change industry in the United States. This myth is also sometimes known as the "Cheap Insurance Myth."

The 3000 Mile Fact
There are still vehicles that need 3K oil changes, but it's not because the oil goes bad after 3K miles. One example is the Saturn S series. These vehicles have a timing chain system that is very sensitive to clean oil because oil pressure is used as hydraulic fluid to ratchet up the timing chain tensioner. If varnish forms in the timing chain tensioner bore then this system can fail and the chain will become loose and eventually break. Dealers have gone as far as tearing out the normal service schedule (6000 miles) and leaving only the severe service schedule. If your engine is destroyed (under warranty) by a failed timing chain then the dealer will legitimately request evidence of oil changes. Unfortunately this problem usually won't manifest itself during the warranty period.

The Dark Oil Myth
Dark oil does not indicate the need for an oil change. The way modern detergent motor oil works is that minute particles of soot are suspended in the oil. These minute particles pose no danger to your engine, but they cause the oil to darken. A non-detergent oil would stay clearer than a detergent oil because all the soot would be left on the internal engine parts and would create sludge. If you never changed your oil, eventually the oil would no longer be able to suspend any more particles in the oil and sludge would form. Fortunately, by following the manufacturer's recommended oil change interval, you are changing your oil long before the oil has become saturated. Remember, a good oil should get dirty as it does it's work cleaning out the engine. The dispersant should stop all the gunk from depositing in the oil pan.

The only real way to determine whether oil is truly in need of changing is to have an oil analysis performed. Since most people don't want to bother with this, it's acceptable to err heavily on the safe side and simply follow the manufacturer's recommended change interval for severe service. There are still a few cars that specify 3K intervals for severe service, but not many. If you look at countries other than the U.S., the oil recommended change interval is much higher than even the normal interval specified by vehicle manufacturers in the U.S.

Severe Service versus Normal Service
Each manufacturer specifies what constitutes normal and severe service. Generally, severe service consists of operating the vehicle in a very muddy or dusty areas (because dust particles get through the air filter and contaminate the oil more quickly), operating the vehicle in a very hot areas (heat breaks down oil more quickly), using the vehicle only for short trips in cold weather (the moisture in the oil never gets vaporized), or using the vehicle for towing or when carrying a car-top carrier. You'll often see claims such as "everyone falls into the severe service category," but these claims are untrue (follow the money and see who's making these claims). If you primarily do freeway driving in moderate weather you do not fall into the severe service category. If you're in doubt, the best way to see if you fall into the severe service category is to have an oil analysis done at the mileage of the severe service interval. Many people just like to play it safe and follow the severe service schedule, which is fine, but there is no benefit in changing the oil sooner than the severe service schedule states.

Maintenance Schedules Vary by Country
Different countries have different maintenance schedules, even for the same car. This fact has been the cause of long argument threads on Usenet. How could the exact same car need a different service schedule simply because of where the vehicle is used? At least part of the reason is due to the differences in fuel. For example, the U.S. and Canada has fuel with high sulphur levels which can cause more oil contamination. Japanese fuel has very low sulphur levels. Europe is in-between. Some of the newer engine technology (direct injection) which raises fuel economy, requires low sulphur fuel. Of course the oil companies have a vested interest in not lowering the sulphur as it adds to refining cost and enables more fuel efficient engines. Since "Big Oil" is in bed with the un-elected president in the U.S., don't expect any action of lower sulphur fuel for a while in the United States. If Al Gore is re-elected in 2004, and the Supremes don't simply ignore the election results again, then there is a chance for lower sulphur fuel in the U.S. beginning in 2005.

Oil change intervals with synthetic oil
Synthetic oils withstand higher temperatures before breaking down, and have more base stock and less viscosity modifiers. Synthetics wear out, become acidic, and eventually become saturated with suspended soot particles, just like regular oil. Again, an oil analysis is a good investment to determine the optimum oil change interval. Never exceed the manufacturer requirements for normal service.

Filter Change Interval
Back in the days of 3000 mile oil changes many manufacturers recommended filter changes only half as often because the filter did not become clogged with dirt at only 3000 miles. This was good advice back then, especially because with non-detergent motor oils a lot of the sludge remained stuck to internal engine parts rather than being carried in the oil to the filter. Nowadays the filter should be changed at every oil change. There are some people who believe so much in synthetic oil that they change filters without changing the oil. There's no harm in changing the filter without changing the oil, but there is no point in doing this.

Do-it-yourself versus paying someone to do it
Oil changes are pretty inexpensive when done at a reputable repair shop or dealer. Most dealers offer oil change specials that cost less than the quick-change oil places, and the dealers do a better job and use better filters. Where I live the dealers have very long service department hours including on Saturday (some on Sunday). The dealers also offer a time guarantee, generally that they'll get you in and out in less than 30 minutes or the next oil change is on them. Another advantage of having it done at a repair shop or dealer is that you have solid legal proof of the date and mileage when the oil change took place. My personal preference is to have the oil changed at a dealer during the warranty period. Edmunds has a page on secret warranties that states: "If you service your vehicle through an independent or aftermarket facility, what does the manufacturer owe you in terms of assistance? Manufacturers cannot control the quality of the parts used or work performed when you service your vehicle through aftermarket service facilities. Also remember that the treatment you receive as a customer has a great deal to do with you being a loyal customer to the dealer and the manufacturer." See: http://www.edmunds.com/advice/fiw/ar...8/article.html .

06-02-09, 06:15 PM

outtamyway

Re: '09 CTS AWD 3.6 oil change

I knew I was opening myself up for the 1K mile oil change argument, but for me, I'm old school and I simply feel better being safe than sorry as I will never have to wonder whether I should have or not. As far as the money, it's cheap insurance. I will allways believe that there are some bits of metal or other crap stuck in some passage way that someone didn't take the time to flush out or clean properly like I would prior to sealing an engine. That's just my humble opinion. TIFWIW

my 2008 cts ..(10/07 build date) does not have that lower shroud you show. i picked car up new from dealer in 11/07 and its never been on there. i've changed the oil & filter twice myself since i bought it 11,600 miles ago. car gets good gas mileage. maybe this lower shroud isn't even needed. any thoughts?

06-03-09, 10:48 AM

outtamyway

Re: '09 CTS AWD 3.6 oil change

Brambo
It would seem that with the dipstick oil level markings indicating low to high being approx. one quart one could conclude that it is not very close to the bottom of the pan. I would guess that the pump drain hose is longer than the OEM dipstick and therefore it should extend pretty close to the bottom. I guess you could record the amount of oil that it takes with a fully drained conventional oil change vs. the dipstick method.
Someone might have already done this?

As far as Don's shroud not being there, I guess I would ask the dealer for it as the manufacturer obviously thought it was a good idea. They don't usually add cost to a car unless it has a valid purpose. Of course you have been driving the car without it and one could conclude that it isn't really needed but I would guess that it might for aerodynamics or ground effects? Certainly not a true skid pan to protect the oil pan/transfer case but it could deflect some debris I suppose.

As far as when and/or how often I change the oil in my car, I don't need an engine analysis or a dissertation as I have been around race cars and wrenched for AA FC (funny cars) long enough to know when and why I need my oil changed. I don't subscribe to the argument that "if people would be content to do it only when it provides some benefit to the vehicle it would be better". Maybe we need a law or tax imposed on us if we change are oil sooner than the Europeans do or when the government says to. (If only Al Gore would have won.) LOL! The Saturn S series example referenced only lends credence to that fact that clean oil does make a difference. Finally I don't see why my previous post stating my position on oil change intervals was censored? I guess this board is run by NBC. If it doesn't fit into their leanings, it doesn't get on the news.

06-03-09, 12:04 PM

Oldschooler08

Re: '09 CTS AWD 3.6 oil change

As far as the plastic shroud underneath I ditched that and all of those engine covers under the hood. IMO if it doesn't provide anything more than decoration and it doesn't make it go faster, it's gone. underhood and underneath shouding doesn't do anything performance wise for the car except trap heat in. Perhaps it's there to quiet down the direct injection ticking. Anyway, my C6 Z06 didn't have them and it was a 200mph car so I would figure aerodynamics is not the reason. All of that will have to come off anyway when D3 gets us that supercharger we've been asking for!

06-03-09, 12:10 PM

crystal_red

Re: '09 CTS AWD 3.6 oil change

I have a friend that used to work at the Lansing plant up until a while ago and he has told me the upper and lower shrouds are there primarily for noise reduction. Cadillac R&D was and is very big on quiet, and have put a lot into noise damping in their vehicles. Beyond that it's only eye candy for those that think so.

06-03-09, 12:21 PM

crystal_red

Re: '09 CTS AWD 3.6 oil change

outtamyway - I'm not trying to be confrontational here, I'm just posting facts.
No one is saying you can't change your oil whenever you want, just that it is not necessary. I used to road race both GTU and GTO cars sponsored under IMSA and we changed oil before every race (and a lot of other things too), but we were running very tight engines at high RPM for a very long time.
I know you love your CTS just as I love mine.
ENJOY and change your oil as often as you wish! :thumbsup:

06-03-09, 10:44 PM

donaldw9521

Re: '09 CTS AWD 3.6 oil change

i did go by the dealer today, and talked to a mechanic in the shop ,and he said that he has seen lots of the cts's without the botom shroud. i'm bringing it in tomorrow for the radio upgrade fix.( keeps switching from radio to aux. input on its own. then i have to hit fm button to get it back to radio)..i agree with you outtamyway about oil change&filter. i'm old/fashioned, i change it (myself) every 3500 miles or 6 to 8 months aprox.(talk about old fashioned) i use 2 2x12s X 3 ft. for ramps so i can chock the hight i need so as to not scrape spoiler...Works for me.

06-05-09, 04:33 PM

Z71

Re: '09 CTS AWD 3.6 oil change

I am reading a survey published in NOIN (quick lube industry publication) and a few interesting facts are mentioned in the quick lube customer survey.

Quote
Oil change frequency is a hot topic these days, with the fast lube industry facing year after year of declining car counts.

32% of customers change their oil whenever the sticker on their windshield tells them to. (Incentive for them to stick a 3 month/3,000 change oil sticker on the windshield)

On average customers changed oil 3.05 times per year

38.7% said they follow the age-oil 3,000 miles interval

Only 16% adhere to the oil monitoring systems

13.3% follow the owners manual

06-05-09, 05:17 PM

GMFAN

Re: '09 CTS AWD 3.6 oil change

outtamyway,
Great report and illustration's. Thanks for taking the time and sharing. :yup:

I'm with Sub on this one. Here is what our old Guru (A GM powertrain engineer) had to say about the OLM. In the mean time, take it out and give it some good ole WOT. If that cures it, it's cold carbon rap.

"One thing I can touch on and clear up.....the GM oil life monitor operation and my statement that ZDP (or ZDDP as you tend to call it here...most of the API literature just sticks to ZDP so I tend to use that) depletion is the basis for oil deterioration.

My spelling is poor but ZDP stands for zinc dialkyldithiophosphate which , as it sounds, is an anti-wear compound comprised of zinc and phosphorus.

ZDP is dispersed in the oil so as to be at a potential wear site if a surface asperity happens to break thru the oil film thickness causing the dreaded metal-to-metal contact. A molecule of ZDP must be present at that moment to prevent microwelding at the contact site which will cause material transfer, scuffing, scoring, wear and catostrophic failure. The concentration of ZDP in the oil will determine if there is ZDP present to work it's magic. The greater the concentration...the more likely a molecule of ZDP will be there...and vice versa.

By nature, ZDP is sacrifical. As ZDP is "used up" at a wear site to prevent micorwelding the concentration of ZDP decreases.... So...if you measure the ZDP concentration in engine oil in a running engine it will decrease at linear rate based on engine revolutions. Any given engine has a certain number of high potential wear areas where metal-to-metal contact could occur due to reduced film thickness and/or surface asperities....areas such as rubbing element cam followers, distributor gears, rocker arm pivots, push rod tips, etc...... The more of these areas the more ZDP depletion. The more often these features come in contact the greater the ZDP depletion. That is why, generally speaking, ZDP concentration in the oil, for any given engine, will decrease at a fairly linear rate when plotted versus cummulative engine revolutions. The more times it turns the more contact the more chance for wear the greater the depletion. This is as much of a fact as I could quote ever and is really not speculation or anything. It is proven beyond a shadow of a doubt in many studies. That is why it is ONE of the basis for determining oil life remaining and why it is THE basic premis of the GM oil life algorithm. It is only ONE of the things that determines oil life...but it is the one thing that can be tied to engine operation in a linear fashion and estimated very accurately by accumulating engine revolutions via a counter.

The GM engine oil life monitor counts engine revolutions and accumulates the number for the basis of the oil life calculation. It then adds deterioration factors for operating temperature, start up temperature, soak times, ambient, coolant temperature, etc... There are a LOT of factors that "adjust" or affect the slope of the deterioration but the fundamental deterioration is traced back to the ZDP depletion that is inescapable with engine revolutions. The specific rate of ZDP depletion is readily measurable for any given engine so that is the fundamental item that is first calibrated for the oil life algorithm to tailor it specifically to that engine.

You would obviously like to get the oil out of the engine before the ZDP concentration gets so low that it is ineffective at being at the right place at the right time and preventing engine wear so that becomes the long term limit on oil life for that application.

The other things that determine oil life such a acid build up, oxidation, petane insuluables such as silicon from dust/dirt, carbon or soot build up from the EGR in blowby, water contamination, fuel contamination, etc.... are all modeled by the multipliers or deterioration factors that "adjust" the immediate slope of the line defined by the engine revolution counter as those items can be modeled in other ways and accounted for in the immediate slope of the ZDP depletion line.

The algorithm was developed over the course of many years by several lubrication experts at GM Fuels and Lubes, spearheaded by Doctor Shirley Schwartz who holds the patents (with GM) for the algorithm and the oil life montitor. I had the luck of working directly with Dr. Schwartz when the idea of the oil life monitor first progressed from the theoretical/lab stage to real world testing/development/validation. There were fleets of cars operated under all conditions that deteriorate the oil life for any and every reason and , thru oil sampling and detailed analysis of the oil condition, the algorithm was developed, fine tuned and validated to be the most accurate way invented yet to recommend an oil change interval by. As just one example, I have seen cars driven side-by-side on trips, one towing a trailer and one not, for instance, to prove the effectiveness of the oil life monitor in deteriorating the oil at a faster rate just because of the higher load, higher average RPM, higher temps, etc...and it works flawlessly.

The oil life monitor is so effective because: it is customized for that specific vehicle/engine, it takes everything into account that deteriorates the oil, it is ALWAYS working so as to take into account THAT INDIVIDUALS driving schedule, and it tailors the oil change to that schedule and predicts, on an ongoing basis, the oil life remaining so that that specific individual can plan an oil change accordingly. No other system can do this that effectively.

One thing is that I know personally from years of testing and thousands of oil analysis that the oil life algorithm works. There is simply no argument to the contrary. If you don't believe me, fine, but, trust me, it works. It is accurate because it has been calibrated for each specific engine it is installed on and there is considerable testing and validation of the oil life monitor on that specific application. NOt something that oil companies or Amsoil do. They generalize....the oil life monitor is very specific for that application.

Oil condition sensors in some BMW and Mercedes products are useful, also. They have their limitations, though, as they can be blind to some contaminates and can, themselves, be contaminated by certain markers or constituents of certain engine oils. Oil condition sensors can only react to the specific oil at that moment and they add complexity, cost and another potential item to fail. One other beauty of the GM oil life monitor is that it is all software and does not add any mechanical complexity, mass, wiring or potential failure mechanism.

There is considerable safety factor in the GM oil life monitor. Typically, I would say, there is a 2:1 safety factor in the slope of the ZDP depletion curve....in other words, zero percent oil life per the ZDP depletion is not zero ZDP but twice the concentration of ZDP considered critical for THAT engine to operate under all conditions reliably with no wear. This is always a subject of discussion as to just how low do you want the ZDP to get before the oil is "worn out" if this is the deciding factor for oil life. We would tend to be on the conservative side. If the oil life is counting down on a slope that would recommend a 10K change interval then there is probably 20K oil life before the ZDP is catostrophically depleted....not that you would want to go there...but reason why many people are successful in running those change intervals.

Please...NOT ALL ENGINES ARE THE SAME. The example above is an excellent practical justification of why you would want to add EOS and change the 15W40 Delvac in the muscle car at 3000 miles max and yet can run the Northstar to 12500 easily on conventional oil. You must treat each engine and situation differently and what applies to one does not retroactively apply to others. This is where Amsoil falls short in my book by proposing long change intervals in most everything if you use their oil. It just doesn't work that way. You can run the Amsoil to 12500 with no concerns whatsoever in the late model Northstar because even the oil life monitor tells you that for conventional oil off the shelf. Would I do that to the 502 in my 66 Chevelle...NO WAY. Amsoil says I can though. Wrong.

There are entire SAE papers written on the GM oil life monitor and one could write a book on it so it is hard to touch on all aspects of it in a single post. Hopefully we hit the high spots. Realize that a GREAT deal of time, work and energy went into developing the oil life monitor and it has received acclaim from engineering organizations, petroleum organizations, environmental groups all across the board. It is not some widget invented in a week and tacked onto the car."

09-07-12, 02:03 AM

jbelot

Re: '09 CTS AWD 3.6 oil change

Wow, thats a ton of info on oil changes. I use the counter on my car. I try to get it in once I am under 20% The dealer doesnt like that but now I know it's the right thing to do. I do a ton of highway miles and change my oil about 2-3 times a year. Im on my second Cadillac CTS and no issues at all.

09-07-12, 02:43 PM

Cadillac Cust Svc

Re: '09 CTS AWD 3.6 oil change

Jbelot, I'm happy that the wealth of information on this site was able to help you! If you'd ever like assistance following up with your dealer for you, I'm happy to do so. My email is Katie_Lucille@gmexpert.com.